The present invention relates to an RFID (Radio Frequency Identification) tag for wirelessly transmitting information such as ID (Identification) recorded in an IC chip.
An RFID tag comprises an IC chip and an antenna and can wirelessly transmit information such as an ID number recorded in the IC chip from the antenna. Accordingly, when communicating with the RFID tag using a reader/writer, information recorded in the IC chip can be read without contact. Thanks to radio transmission, information on IC chips can be read even in articles stored in a bag or box. Therefore, the RFID tag is widely used for manufacturing management and logistics of articles. In the management, the management of CD (Compact Disk), being an optical disk for use in music, or DVD (Digital Versatile Disk), being an optical disk for use in video, such as movies is included. In recent years, management enhancement of sensitive information and personal information is being promoted and the application of the RFID tag to disk media such as the CD and DVD having stored therein the information is being promoted. In reality, a data reading speed of these disk media increases and the rotation speed of the disk media exceeds 10000 rpm. It is needed to reduce the displacement of a center of gravity (hereinafter, referred to as a mass eccentricity) of the disk medium including the RFID tag.
U.S. Pat. No. 6,359,842 B1 discloses that when relative to the mass eccentricity due to the attaching of the IC chip to the disk, a balancer is provided at a position being point-symmetric to the IC chip with the center of the disk as the starting point, the amount of mass eccentricity is reduced.